Burmese opposition leader Aung San Suu Kyi has been forced to suspend her campaign for a seat in parliament because of ill health, her party has said.

Ms Suu Kyi, who is running for a seat in parliament in the April 1 polls, was put on a drip and ordered to rest by her doctor after falling ill in the town of Myeik in Burma's far south.

Looking tired and drawn, she arrived at Rangoon airport after cutting short her visit, saying only that she was "not well".

Her doctor, Tin Myo Win, said Ms Suu Kyi was getting better, but that he had asked that she cancel a final campaign trip on Tuesday and Wednesday to Magway, the central Burmese region where her independence hero father was born.

"She is recovering, but she needs to rest for at least a week," he said.

An increasingly frail-looking Ms Suu Kyi has been briefly taken ill once before during her gruelling schedule of rallies and speeches across the country.

The health of the opposition leader is likely to be a source of anxiety for the tens of thousands of supporters who have thronged to see her at almost every stage of the campaign.

Dr Tin Myo Win said Ms Suu Kyi had became exhausted and suffered vomiting and low blood pressure on Saturday after the boat she was travelling in got stuck on a sandbank for several hours during her trip in the south.

She pressed ahead with a final rally in Myeik on Sunday and was cheered by tens of thousands as she urged supporters to vote for her National League for Democracy party, according to a photographer at the scene.

"I'm trying to keep in good health," she told the crowd, apologising for making only a brief speech before rushing to catch a flight back to Rangoon.

"I have been encouraged by the people," she said.

A statement from the NLD confirmed the decision to cancel this week's Magway trip.

The polls next week are the first time Ms Suu Kyi, whose Kawhmu constituency is near Rangoon, has been able to stand for election in a country dominated by the military for decades.